Ad hoc networks include a plurality of nodes, many of which are mobile, in wireless communication with one another. The topology of ad hoc networks varies as the nodes move with respect to each other, coming in and out of range of each others' transmitters. Typically, nodes in ad hoc networks schedule their communications with each other using various time division and/or frequency division multiplexing schemes.
In practice, a communication device using a periodic TDMA communications protocol remains in one of two states, transmit or receive. To remain in either state, the communication device supplies power to a transceiver. For many communication devices, the device is predominantly idle, waiting in a powered receive state in case an incoming message arrives. A deficiency of this approach is that in low network traffic environments, the amount of energy used in an idle receive state dominates the total energy used by the communication device.